title: Combined measurement of N-terminal pro-B-type natriuretic peptide and highly sensitive cardiac troponin T for diagnosis and monitoring of heart injury in chronic Chagas' disease.
abstract: OBJECTIVE
  Chronic Chagas disease afflicts millions of patients in Latin America of which 70% remain asymptomatic but 30% develop fatal heart injury. To evaluate the impact of laboratory medicine for diagnosis and guiding of patients with Chagas' heart disease, we measured N-terminal B-type natriuretic peptide (NT-proBNP) and cardiac troponin T (cTnT).
  
  
  METHODS
  NT-proBNP and cTnT using the highly sensitive assay (hs-cTnT) were measured in 48 asymptomatic Chagas' patients (control group; (-) CM), and in symptomatic patients who suffered from mild/moderate (group (+/++) CM, n=62) or severe cardiomyopathy (group (+++) CM, n=27).
  
  
  RESULTS
  Both markers were higher in (+/++) CM and (+++) CM vs. (-) CM and increased in the cardiomyopathy severity. Values of 3 ng/L cTnT and 160 ng/L NT-proBNP were calculated as optimal cut-offs to distinguish (-) CM vs. CM. The NT-proBNP cut-off of 125ng/L, as recommended by international guidelines, was additionally incorporated in the analysis. Cardiomyopathy was most successfully predicted by dual positivity of both markers (positive predictive value=1.0). Negativity of both markers effectively excluded cardiomyopathy (negative predictive value of 0.85). Positivity for at least one of the markers is the best for overall correct classification.
  
  
  CONCLUSIONS
  Combined measurement of hs-cTnT and NT-proBNP can be used for diagnosis and monitoring of cardiomyopathy in chronic Chagas' patients. In this way, laboratory medicine increases the pre-test probability of the cardiologic diagnostics, which would reduce its time, cost, and logistical problems.
authors.affiliation: Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Silvia Gilka
authors.initials: SG
authors.lastname: Munoz Saravia
authors.forename: Annekathrin
authors.initials: A
authors.lastname: Haberland
authors.forename: Sabine
authors.initials: S
authors.lastname: Bartel
authors.forename: Raul
authors.initials: R
authors.lastname: Araujo
authors.forename: Gregorio
authors.initials: G
authors.lastname: Valda
authors.forename: Diana Duchen
authors.initials: DD
authors.lastname: Reynaga
authors.forename: Ivan Diaz
authors.initials: ID
authors.lastname: Ramirez
authors.forename: Adrian C
authors.initials: AC
authors.lastname: Borges
authors.forename: Gerd
authors.initials: G
authors.lastname: Wallukat
authors.forename: Reinhard
authors.initials: R
authors.lastname: Ziebig
authors.forename: Ingolf
authors.initials: I
authors.lastname: Schimke
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002598:Chagas Cardiomyopathy / Q000097:blood / Q000175:diagnosis*; D002908:Chronic Disease; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis; D012720:Severity of Illness Index; D020107:Troponin T / Q000097:blood*
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; D020107:Troponin T; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain
keywords: B-type natriuretic peptides; Cardiac troponins; Cardiomyopathy; Chagas' heart disease; Chronic Chagas' disease; NT-proBNP; hs-cTnT